Installing the GFA-6002 and GFA-6006
During normal home operation the internal heatsinks of the GFA-6002/ 6006 may become warm. However, there are instances during high-level playback into low impedances when the heatsinks will become much warmer than usual. To ensure the amplifier’s long-term, trouble-free operation it is necessary to provide adequate ventilation for the heatsinks. Therefore, the GFA-6002/6006 should be kept away from external sources of heat such as radiators and hot-air ducts. The GFA-6002/6006 should never be placed with other heat-producing components in a cabinet or enclosure lacking free air flow. The top and bottom panel of the amplifier’s chassis have been provided with vents to allow the necessary cooling of the internal components. It is imperative that these vents are not obstructed in any way.
We recommend that you do not stack other components on top of the GFA-6002/6006. This is particularly important if your system includes low-impedance loudspeakers which are difficult to drive, or if you will consistently demand high volume levels from the amplifier and speaker system. Not only will heat generated by the amplifier affect the performance of equipment stacked on top of the GFA-6002/6006, but the free flow of air through the ventilating slots in the amplifier may be partially obstructed.
If you observe these recommendations, the GFA-6002/6006 will perform reliably in any reasonable environment. You should also pay attention to such normal considerations as protection from excessive dust and moisture. Occasional vacuuming of accumulated dust on the chassis, panels and around the ventilating slots should be all that is required.
The optimal performance of your new
GFA-6002/6006 will ultimately depend on the care with which you make the connections between the amplifier, pre-amplifier, surround sound decoder and the loudspeakers. All input and output signal connections should be made only with high quality, low-loss, low capacitance cables following the recommendations in the Inputs and Outputs section of CONNECTING THE GFA-6002/6006.
Connecting the GFA-6002 and GFA-6006
When connecting the amplifier to the loudspeaker, it is vital to maintain proper polarity (positive to positive, negative to negative). On the GFA- 6002/6006, the positive terminal is color coded RED and labeled “+,” and the negative is color coded BLACK and labeled “-”. The positive terminal on the speaker will be color coded RED, or will be labeled “+,” “pos,” “positive,” “8 ohms” or “4 ohms.” The negative terminal on the speaker will be color coded BLACK, or will be labeled “-,” “neg,” “negative,” “C,” “Common,” “G,” or “ground.”
We recommend that your speaker cables be terminated with “U” type spade connectors. These will give the most contact area insuring long-term reliability. The spade connector should have a maximum width of 0.57 inches and an opening width of no less than 0.25".
To properly connect the speaker cable to the binding posts, turn the insulated head of the binding post clockwise until the wire or connector is firmly secured. Finger pressure is sufficient and you should not use pliers or other tools which could damage or over-tighten the binding-post assembly. The binding posts have been designed in such a way that finger pressure is all that is required to cause a “pinching” action among the different metal surfaces to ensure proper connection.
It is very important to use the correct size of wire in order to avoid unnecessary loss of amplifier power in the cable, reduction of amplifier damping factor and other undesirable conditions. Sound audio engineering practice suggests the use of at least AWG16, stranded, copper cable. Recommended capacitance of the speaker wire should not exceed 5OpF per foot. This insures high frequencies will not be rolled off.
All loudspeakers having a nominal impedance down to 4 ohms can be connected to and driven by the GFA- 6002/6006. The amplifier can drive these low-impedance speakers at more than adequate power levels with no difficulty. It should be noted that many loudspeaker systems which are nominally rated at 4 ohms drop in impedance, in some parts of their frequency range, to as low as 2 ohms (and sometimes less). You will not experience difficulties even with these very low impedance loads unless you demand excessively high volume levels from your system.
We do not recommend that you run multiple sets of speakers to each speaker output on the GFA-6002/6006. Instead, we recommend that you use a multiple speaker selector such as the ADCOM GFS-300 or GFS-600. A speaker selector enables you to maintain good sonic integrity while giving you the flexibility to add speakers throughout your house and maintain proper impedance levels to help prevent over heating of the amplifier.
Finally, we suggest that you follow this chart for speaker wire lengths and gauges. If longer runs are needed, it is best to consult with your ADCOM Dealer to maximize the performance of your system with your exact conditions.
up to 24 feet — AWGI6 up to 36 feet — AWGI4 up to 58 feet — AWGI2
